全文获取类型
收费全文 | 2719篇 |
免费 | 185篇 |
国内免费 | 2篇 |
出版年
2022年 | 12篇 |
2021年 | 29篇 |
2020年 | 14篇 |
2019年 | 16篇 |
2018年 | 20篇 |
2017年 | 20篇 |
2016年 | 44篇 |
2015年 | 66篇 |
2014年 | 78篇 |
2013年 | 123篇 |
2012年 | 128篇 |
2011年 | 122篇 |
2010年 | 81篇 |
2009年 | 78篇 |
2008年 | 146篇 |
2007年 | 142篇 |
2006年 | 119篇 |
2005年 | 130篇 |
2004年 | 145篇 |
2003年 | 124篇 |
2002年 | 127篇 |
2001年 | 112篇 |
2000年 | 102篇 |
1999年 | 64篇 |
1998年 | 34篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 30篇 |
1994年 | 17篇 |
1993年 | 14篇 |
1992年 | 57篇 |
1991年 | 60篇 |
1990年 | 46篇 |
1989年 | 79篇 |
1988年 | 58篇 |
1987年 | 42篇 |
1986年 | 42篇 |
1985年 | 53篇 |
1984年 | 24篇 |
1983年 | 31篇 |
1982年 | 26篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 20篇 |
1978年 | 15篇 |
1977年 | 16篇 |
1975年 | 12篇 |
1973年 | 16篇 |
1972年 | 11篇 |
1968年 | 9篇 |
排序方式: 共有2906条查询结果,搜索用时 15 毫秒
971.
Toyomi Yamazaki Miki Sagisaka Riko Ikeda Toshiyuki Nakamura Noriko Matsuda Takeshi Ishii 《Bioscience, biotechnology, and biochemistry》2013,77(10):1753-1756
We purified several hundred mgs of four major theaflavins (theaflavin, theaflavin-3-O-gallate, theaflavin-3′-O-gallate, and theaflavin-3,3′-O-digallate). Among the 25 hTAS2Rs expressed in HEK293T cells, hTAS2R39 and hTAS2R14 were activated by theaflavins. Both hTAS2R39 and hTAS2R14 responded to theaflavin-3′-O-gallate. In addition, hTAS2R39 was activated by theaflavin and theaflavin-3,3′-O-gallate, but not by theaflavin-3-O-gallate. In contrast, hTAS2R14 responded to theaflavin-3-O-gallate. 相似文献
972.
Keiko Fujimoto Sanae Nakashima Shotaro Uchida Riham N.S. Amen Yuji Ishii Yuko Hirota Yoshitaka Tanaka 《Biochemistry and Biophysics Reports》2020
HM1.24 (also known as BST-2, CD317, and Tetherin) is a type II single-pass transmembrane glycoprotein, which traverses membranes using an N-terminal transmembrane helix and is anchored in membrane lipid rafts via a C-terminal glycosylphosphatidylinositol (GPI). HM1.24 plays a role in diverse cellular functions, including cell signaling, immune modulation, and malignancy. In addition, it also functions as an interferon-induced cellular antiviral restriction factor that inhibits the replication and release of diverse enveloped viruses, and which is counteracted by Vpu, an HIV-1 accessory protein. Vpu induces down-regulation and ubiquitin conjugation to the cytoplasmic domain of HM1.24. However, evidence for ubiquitination site(s) of HM1.24 remains controversial. We demonstrated that HM1.24 is constitutively poly-ubiquitinated at the N-terminal cytoplasmic domain, and that the mutation of all potential ubiquitination sites, including serine, threonine, cysteine, and lysine in the cytoplasmic domain of HM1.24, does not affect the ubiquitination of HM1.24. We further demonstrated that although a GPI anchor is necessary and sufficient for HM1.24 antiviral activities and virion-trapping, the deleted mutant of GPI does not influence the ubiquitination of HM1.24. These results suggest that the lipid raft localization of HM1.24 is not a prerequisite for the ubiquitination. Collectively, our findings demonstrate that the ubiquitination of HM1.24 occurs at the N-terminal amino acid in the cytoplasmic domain and indicate that the constitutive ubiquitination machinery of HM1.24 may differ from the Vpu-induced machinery. 相似文献
973.
974.
975.
The purpose of this study was to investigate the effect of blood flow-restricted training (BFRT) on jump performance in relation to changes in muscle strength. Seventeen untrained young men were assigned into either BFRT or normal training (NORT) groups and performed low-intensity [30-40% of one-repetition maximum (1RM)] resistance exercise (horizontal squat, 3-4 sets × 15-30 repetitions) twice a week for 10 weeks. The BFRT performed the exercise with their proximal thighs compressed by air-pressure cuffs for the purpose of blood flow restriction. Squat 1RM, muscle cross-sectional area (CSA) of quadriceps femoris, and countermovement jump (CMJ) height were measured before and after the 10-wk training period. Squat 1RM increased greater in BFRT than in NORT (19.3% vs. 9.7%, P < 0.01). Although the CSA increase was independent of groups, it tended to be larger in BFRT than in NORT (8.3% vs. 2.9%, P = 0.094). On the other hand, CMJ height did not change after the training (P = 0.51). In conclusion, the present study showed that BFRT induced muscle hypertrophy and strength increase, whereas it did not increase CMJ height in previously untrained young men. It is suggested that BFRT is ineffective in improving jump performance. 相似文献
976.
977.
Takahiro Ishii Hiroshi Matsuura Kunimitsu Kaya Charles Santhanaraju Vairappan 《Biochemical Systematics and Ecology》2011,39(4-6):864-867
Biochemical Systematics and Ecology, Volume x, Issue x, Pages x–x (dd mm yyyy). A new bisabolane-type sesquiterpenoid from Curcuma domestica. Takahiro Ishii, Hiroshi Matsuura, Kunimitsu Kaya, Charles Santhanaraju Vairappan.Highlights? Chemical constituents of lowland and highland Curcuma domestica of Borneo are reported. ? Three sesquiterpenes and three curcuminoids secondary metabolites were found in common. ? Highland populations contained two additional bisabolane-type sesquiterpenoid metabolites. ? Curcuma domestica is reported as a new source for novel compound, bisacurol B. 相似文献
978.
Ogawa K Takemoto N Ishii M Pasquale EB Nakajima T 《Histochemistry and cell biology》2011,136(6):617-636
Eph receptors and ephrin ligands are membrane-bound cell–cell communication molecules with well-defined roles in development.
However, their expression and functions in the gastric epithelium are virtually unknown. We detected several EphB receptors
and ephrin-Bs in the gastric corpus mucosa of the adult rodent stomach by RT-PCR amplification. Immunostaining showed complementary
expression patterns, with EphB receptors preferentially expressed in the deeper regions and ephrin-Bs in the superficial regions
of the gastric units. EphB1, EphB2 and EphB3 are expressed in mucous neck, chief and parietal cells, respectively. In contrast,
ephrin-B1 is in pit cells and proliferating cells of the isthmus. In a mouse ulcer model, EphB2 expression was upregulated
in the regenerating epithelium and expanded into the isthmus. Thus, EphB/ephrin-B signaling likely occurs preferentially in
the isthmus, where receptor-ligand overlap is highest. We show that EphB signaling in primary gastric epithelial cells promotes
cell retraction and repulsion at least in part through RhoA activation. Based on these findings, we propose that the EphB-positive
progeny of gastric stem cells migrates from the isthmus toward the bottom of the gastric glands due to repulsive signals arising
from contact with ephrin-Bs, which are preferentially expressed in the more superficial regions of the isthmus and gastric
pits. 相似文献
979.
Okada T Kawakami S Nakamura Y Han KH Ohba K Aritsuka T Uchino H Shimada K Sekikawa M Ishii H Fukushima M 《Bioscience, biotechnology, and biochemistry》2011,75(7):1335-1341
The effects of betaine supplementation on D-galactosamine-induced liver injury were examined in terms of hepatic and serum enzyme activities and of the levels of glutathione and betaine-derived intermediates. The rats induced with liver injury showed marked increases in serum enzyme activity, but those receiving dietary supplementation of 1% betaine showed enzyme activity levels similar to a control group without liver injury. Administration of betaine also increased both hepatic and serum glutathione levels, even following D-galactosamine injection. The activity of glutathione-related enzymes was markedly decreased following injection of D-galactosamine, but remained comparable to that of the control group in rats receiving 1% betaine. The concentrations of hepatic S-adenosyl methionine and cysteine showed similar trends to that observed for hepatic glutathione levels. These results indicate that 1% betaine has a hepatoprotective effect by increasing hepatic and serum glutathione levels along with glutathione-related enzyme activities in rats. 相似文献
980.
Shiozuka C Taguchi A Matsuda J Noguchi Y Kunieda T Uchio-Yamada K Yoshioka H Hamanaka R Yano S Yokoyama S Mannen K Kulkarni AB Furukawa K Ishii S 《Journal of biochemistry》2011,149(2):161-170
Fabry disease is a lysosomal storage disorder caused by an α-galactosidase A (α-Gal A) deficiency and resulting in the accumulation of glycosphingolipids, predominantly globotriaosylceramide (Gb3). A transgenic mouse expressing the human α-Gal A R301Q mutant in an α-Gal A-knockout background (TgM/KO) should be useful for studying active-site-specific chaperone (ASSC) therapy for Fabry disease. However, the Gb3 content in the heart tissue of this mouse was too low to detect an ASSC-induced effect. To increase the Gb3 levels in mouse organs, we created transgenic mice (TgG3S) expressing human α1,4-galactosyltransferase (Gb3 synthase). High levels of Gb3 were observed in all major organs of the TgG3S mouse. A TgG3S (+/-)M(+/-)/KO mouse was prepared by cross-breeding the TgG3S and TgM/KO mice and the Gb3 content in the heart of the TgG3S(+/-)M(+/-)/KO mouse was 1.4 μg/mg protein, higher than in the TgM(+/-)/KO (<0.1 μg/mg protein). Treatment with an ASSC, 1-deoxygalactonojirimycin, caused a marked induction of α-Gal A activity and a concomitant reduction of the Gb3 content in the TgG3S(+/-) M(+/-)/KO mouse organs. These data indicated that the TgG3S(+/-) M(+/-)/KO mouse was suitable for studying ASSC therapy for Fabry disease, and that the TgG3S mouse would be useful for studying the effect of high Gb3 levels in mouse organs. 相似文献